This invention relates to a humidifier for aqualung equipment for applying moisture to be inhaled by a user.
It is well known that aqualung equipment generally comprises a highly pressurized gas cylinder adapted to be carried on the user's back, a gas supply passage communicating with the gas cylinder, a pressure reducing means for pressure-reducing and bleeding the gas from the gas cylinder into the supply passage, a mouth-piece adapted to be held in user's mouth and receiving pressure-reduced gas through the supply passage, and a respiration control unit operative to substantially enable respiration to be performed in the mouth-piece whereby the gas housed in the cylinder may successively be inhaled by the user while being pressure-reduced. Generally, an oxygen-containing gas is compressed under a pressure of approximately 150 atm within the gas cylinder in order to accommodate a sufficient quantity of gas for long time aquatic respiration. Such high pressure inherently refrains a large quantity of moisture from being contained in the gas trapped in the cylinder of the equipment. Moreover, since the gas when arriving at the mouth-piece has a pressure reduced substantially to 1 atm, i.e., the gas is then expanded approximately by 150 times of the gas trapped in the cylinder, the degree of moisture capable of being contained in the gas per unit of volume at the mouth-piece will be reduced by 1 over 150 times as compared to that in the trapped gas. Accordingly the gas in the mouth-piece may only have a much decreased quantity of moisture. Such dried gas causes the user to suffer an aching thirst. This implies that the user may not remain underwater for a long time or otherwise that such sufferings derived from the dried inhalant gas may be fatal to the user.
Further, such thirst caused by the dried inhalant gas will render it substantially difficult for the user to swallow saliva in order to arbitrarily remove tinnitus ascribed to the action of water pressure.
Accordingly, an object of this invention is to provide a humidifier capable of producing a moistening gas in the mouth-piece of the aqualung equipment.